Conventionally, as disclosed in Patent Document 1, for example, there is known a liquid-level detection device including a float that floats on a surface of liquid, a float arm and an arm holder that rotate due to the vertical movement of the float, and a sensor frame that rotatably supports the arm holder. In such a liquid-level detection device, the sensor frame is provided with a stopper surface. The stopper surface is located on a rotational track of a stopper engagement part provided for the float arm, and is in contact with the stopper engagement part to restrict the rotation of the arm holder.
In addition, three pairs of the stopper surfaces formed in a stepped manner along the axial direction of the stopper engagement part are provided for the sensor frame of Patent Document 1. As a result of such a configuration, by adjusting the length of the stopper engagement part, a rotatable range of the arm holder can be changed to any of the previously-specified three steps corresponding to the shape of a container.